The ZR36067 is a PCI adapter intended for multimedia applica-tions on PCI systems. It supports high rate code (compresseddata stream) transfer between the system memory and JPEG orMPEG processors. Simultaneously to the code transfer, theZR36067 captures digital video, such as decompressed MJPEG(Motion JPEG), MPEG, or the output of a video decoder, andcreates a scaled video window in the graphics display memory.

The ZR36067 provides the host software with full control over alarge number of non-PCI multimedia devices:

· Motion JPEG Codecs - ZR36050+ ZR36016, ZR36060

· Audio codecs

· MPEG and DVD decoders - ZR36110, ZR36700

· I2C devices, such as video decoders, video encoders, etc.

The ZR36067 interfaces directly to the PCI bus. As a busmaster, it transfers data (e.g, JPEG compressed data) to or fromthe system memory, and writes digital video pixels to thegraphics display memory. As a bus target, the ZR36067 reflectsthe host accesses onto a micro-controller-type 8-bit "Guest Bus".

The ZR36067 has a special "Still Transfer" port by means ofwhich the host software writes (or reads) digitized video, as RGBpixels, from the system memory to (or from) the video bus. Thispath enables fast transfer of still images to be compressed (ordecompressed) by the JPEG chip set.

The ZR36067 supersedes the ZR36057 PCI Bus MultimediaController and is recommended for all new designs. TheZR36067 has the same package, pinout and functions and theZR36057, with the following exceptions:

· The ZR36067 supports programmable PCI Subsystem ID

and Subsystem Vendor ID. These ID registers get their val-ues by sampling the state of existing pins of the ZR36067 (Video bus, Guest bus and GPIO pins) at PCI Reset time. Thus, the values can be programmed by means of pull-up or pull-down resistors on these pins. Note that the Subsystem ID and Subsystem Vendor ID registers of the ZR36057 are hard wired to 0.

· Two functional bugs of the ZR36057, documented in its data

sheet, have been corrected in the ZR36067 and work-arounds are no longer required.

The video decoder directs the video in YUV 4:2:2 format, and thevideo synchronization signals, to the video input port of theZR36060. The video is also transferred to the video encoder fordisplay on a TV monitor and simultaneously to the Video FrontEnd of the ZR36067. The ZR36067 can optionally down-scalethe video, convert it to RGB, and transfer the pixels using DMAto the display memory of the host PC. In parallel, the ZR36060performs the JPEG compression. The ZR36050 drives theJPEG code stream to the Codec Front End of the ZR36067,which transfers the compressed video fields using DMA to asystem memory buffer allocated by the host.

1.2.2 Motion Video Decompression

In Motion Video Decompression, the ZR36067 transfers thecode stream from system memory via the ZR36067 Codec FrontEnd to the ZR36060, using DMA. The ZR36060 decompressesthe JPEG code and transfers the video to the video encoder tobe displayed on a TV monitor. The ZR36060 video output isdriven simultaneously to the Video Front End of the ZR36067 tobe processed, as in the compression mode, and transferredusing DMA to the PC display memory.

1.2.3 Still Image Compression

In Still Image Compression mode an image bitmap is written bythe host, pixel by pixel, through the PCI bus to the ZR36067. TheZR36067 transfers the pixels through its video bus port to thevideo input port of the ZR36060. The ZR36067 generates anddrives the required video synchronization signals for theZR36060 in this mode. After the first strip of 8 video lines is filled,the ZR36060 starts performing the raster-to-block operation andcompressing the data, and drives the code stream to theZR36067. The code stream is transferred using DMA to the hostmemory as in Motion Video Compression.

1.2.4 Still Image Decompression

In Still Image Decompression mode, the ZR36067 fetches thecode stream from system memory using DMA, as in MotionVideo Decompression. The ZR36060 reads the compresseddata from the ZR36067, decodes it and send the decompressedvideo to the video port of the ZR36067. From there the hostsoftware reads it out to system memory, pixel by pixel.

Note that still image decompression can also be accomplishedby configuring the ZR36067 in Motion Video Decompressionmode, and transferring the decompressed video to a contiguousbuffer in system memory instead of the display memory. Sincethis has a speed advantage over Still Image Decompressionmode, it is the preferred method for most applications.

5

AV PCI CONTROLLER

1. In this document, an overbar is used to denote active low signals. In other documents referenced herein, such as the PCI specifications, the # suffix notation is often

used instead. The two forms of notation are interchangeable. Thus, for example, DEVSEL is equivalent to DEVSEL#.